I’m sure many readers of Universe Today are like me, fans of the science fiction genre. From the light sabres of Star Wars to the neuralyzer of Men in Black, science fiction has crazy inventions aplenty and once science fiction writers dream it, scientists and engineers try and create it. Perhaps the holy grail of science fiction creations is the warp drive from Star Trek and it is fair to say that many have tried to work out if it is even possible to travel faster than the speed of light. To date, alas, to no avail but if the warp drive eludes us, what about faster than light communication!
Let’s start with the warp drive. The concept is a drive that can propel a spacecraft at speeds in excess of the speed of light. According to the Star Trek writers, the speed was described in factors of warp speed where they are converted to multiples of the speed of light by multiplication with the cubic function of the warp factor itself! Got it! Don’t worry, it’s not crucial to this article. Essentially ‘warp 1’ is equivalent to the speed of light, ‘warp 2’ is eight times speed of light and ‘warp 3’ is 27 times the speed of light and so it goes on! Therein lies the problem; achieving faster than light travel.
In attempts to try to understand this, numerous experiments have been undertaken, of note Bill Bertozzi at MIT accelerated electrons and observed them becoming heavier and heavier until they couldn’t be accelerated any more! Once at the speed of light, it takes an infinite amount of energy to accelerate an object further! The maximum speed he achieved was the speed of light. In other experiments, synchronised atomic clocks were taken on board airliners and found that, after travelling at high speed relative to a reference clock on Earth, time had run slower! The upshot is that the faster you go, the slower time passes and at the speed of light, time stops! If time stops, so does speed! hmmmm this is tricky.
The science of faster than light travel aside, In a number of potential warp drive designs have surfaced like the Alcubierre Drive proposed in 1994. However, the common factor to provide the faster than light travel is something called negative energy which is required in copious amounts. The study of quantum mechanics shows that even empty space has energy and anything that has less energy than empty space has ‘negative energy’. The problem (among many) is that no-one knows how to get negative energy in huge amounts to power the warp drives.
It seems the warp drive is some time away yet but what about faster than light communication, could that work? Accelerating macroscopic objects, like spacecraft requires high amounts of negative energy but communication, as a recent paper explains, which operates at much smaller scale requires less energy. Quite a bit less in fact, less than is contained inside a lightning bolt. Perhaps more tantalising is that we may just be able to create small amounts of negative energy using today’s technology.
One of the ways this can be achieved is to ensure the proper configuration and distribution of negative energy to channel communication. The paper proposes a tubular distribution of negative energy in so called hypertubes to enable the acceleration and deceleration of warp bubbles for superluminal communication. Achieving this for long distance communication will require special devices to be designed and built but as the papers author Lorenzo Pieri concludes “it is tantalising to consider the fabrication of microchips capable of superluminal computing”. Yes, that is an exciting proposition but the thought of firing messages out to the cosmos at speeds faster than that of light.. Just wow!
Source : Hyperwave: Hyper-Fast Communication within General Relativity
I am unconvinced by many statements on both sides of this discussion, all too often humans have made profound claims, that seemed to both make sense and be supported scientifically, only to later come crashing down due to new data, observations or better mathematical calculations.
Our evidence certainly implies true superluminal communication, and travel, is impossible, but who knows what breakthroughs will be made in 1, 5, ,10 or 100 years. Look how far science and technology have come since 1800, far more than in the previous 3000 years or more.
We live in times where science and understanding allows us to make reasonable, but not necessarily accurate, predictions of the future, but unlike the past, these predictions are grounded in real facts, understanding and theories.
The problem with warp drives is not the demand for negative potential energies which in cases other than vacuum is often realized such as by gravitational fields. [The paper however does not describe the normal “dark” potential energy of the vacuum but the more elusive energy density of the full general relativistic system.) But what makes them impossible is the demand for the warp bubble matter to be created and travel at superluminal speeds, which is forbidden by special relativity.
The paper refers to that problem and claims to solve it. But only for warp bubbles of Planck scales which is not especially exciting since a) the uncertainty principle makes them mundane regarding negative energies and negative energy densities and b) they can’t contain anything matter and so no information. (That the paper makes the warp bubbles themselves as the putative quasiparticle force carriers do not solve this problem and sits uncomfortable with quantum field theories where signal carrying particles live.)
The same problem then analogously applies to signals in general, since superluminal signals are also forbidden.
The well known results of special relativity are described as latter experiments in a paragraph oddly filled with exclamation marks.
@James: I agree, apart from the idea of a discussion with two sides. You mention the evidence that has made this a fringe topic.
Oh, I forgot, speaking of the fringe nature of the topic: the paper is an arxiv print with no information suggesting an attempt of peer review publiching.